textproduct: Rapid City

KEY MESSAGES

-Wildfire smoke is expected to linger at least through Saturday

-Dry through Saturday most places, the exception will be across south central SD Sat morning

-Slightly cooler temperatures tomorrow, but back into the upper 90s for the remainder of the weekend

-Unsettled and cooler next week

UPDATE

Issued at 944 PM MDT Thu Aug 6 2026

Cool front will move through tonight dropping highs Friday by 10 to 15 degrees across western SD. Northeast WY will remain warm with highs in the mid 90s. Warm front will shift north Sat, with early morning TS possible across scentral SD. Some storms could produce hail. LL moisture will increase Sunday with ESE LL flow. This will support isolated TS across western SD in the afternoon, mainly around the BH and across northwest SD as a weak shortwave moves through. Frontal boundary will oscillate over the region much of next week with unsettled and cooler conds. Smoke from western wildfires will linger over the region through at least Sat with a thicker batch expected to impact the western third of the FA Sat. Have extended and adjusted smoke mention through Sat.

DISCUSSION

(This Afternoon Through Wednesday) Issued at 1141 AM MDT Thu Aug 6 2026

Current Water Vapor and upper air analysis shows ridge over the far western CONUS, while broad upper trough sits over the plains into the Great Lakes region, with northwest flow over the FA. 17Z surface analysis shows a SW-NE oriented surface trough over western SD early this afternoon. Winds are currently light out of the north on the back side of the trough, while out ahead of it winds are light to breezy out of the south-southwest. Temperatures currently sit in the 80s to low 90s. Skies are a bit hazy from wildfires out west, and hi-rez models keep smoke in the region at least through Friday.

As the trough moves southeast towards more available moisture, a few CAMS show potential for isolated storm development near south central SD late this afternoon into early evening. CAPE values in the 700-1400 j/Kg range, coupled with 30-40kt 0-6km shear, could promote an isolated strong to severe storm if there is any initiation this afternoon. Main concern will be available moisture down there. Models do hint at a LLJ setup both overnight tonight and Friday night. For tonight, CAMS don't point towards any development tonight, given the dry air. Early Saturday morning may be more concerning, with better moisture advection, models do point towards a higher potential for overnight storms with a a chance for severe. Currently models show the best location for storms early Saturday morning around south central SD.

Upper ridge flattens out a bit over the weekend, prompting slightly cooler temperatures Monday through the remainder of next week, though still in the 80s. With a more zonal upper flow setting up, next week looks a bit more active with shower/storm potential. Especially the latter half of next week, as models point towards better moisture advection into the area.

AVIATION

(For the 06Z TAFS Through 06Z Friday Night) Issued At 1006 PM MDT Thu Aug 6 2026

VFR conditions are expected through the TAF period. Main concern for KGCC will be smoke impacts bringing a slight reduction to slantwise visibility through 07/12z.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.